/Engine/Source/Editor/Sequencer/Public/SequencerUtilities.h
Generates a uniqueFNamefrom a candidate name given a set of already existing names. The name is made unique by appending a number to the end.
static [FName](API\Runtime\Core\UObject\FName) GetUniqueName ( [FName](API\Runtime\Core\UObject\FName) CandidateName, const [TArray](API\Runtime\Core\Containers\TArray)< [FName](API\Runtime\Core\UObject\FName) > & ExistingNames )